Record numbers of students, demands for smaller class size, shrinking budgets, and growing infrastructure costs are spurring demand for portable classrooms in America’s schools. 65% of schools in the West report using portable classrooms and 36% nationwide do so. Over 180,000 students attend school in about 6000 portables in the Northwest and districts installations are increasing at a rate of 5% per year. Nationally, student enrollment is expected to grow throughout the century.

In the Northwest, Building America is funding state energy offices and Pacific Northwest National Laboratory to explore ways of making portable classrooms more efficient and better places to work and learn. As part of the Building America Industrialized Housing Partnership, the states and PNNL are using building science to examine energy consumption, lighting, and ventilation to make these classrooms more comfortable and better value investments.

  Findings to date show that simple, low cost measures can do much to reduce energy costs and increase efficiency. The research team investigated existing classroom retrofits, side-by-side comparisons of energy-efficient and standard units available on the market, and classrooms built to special standards to increase efficiency.

Here are some of the project’s key findings:

• T-8 lighting fixtures with electronic ballasts are cost effective in both new and existing buildings.
• Programmable thermostats only do half the job if they cannot be turned off for holidays. If they can be programmed for automatic holiday shutdown, all the better.
• Additional high-efficiency and operable windows, located on opposite walls, provide needed daylighting and ventilation.
  Building commissioning ensures proper building set up and operation and can be crucial to effective heating and ventilation controls and dampers.

• Heating and ventilation controls that measure air pollutants or carbon dioxide are not effective.
• Air leakage through T-bar ceiling can lead to substantial energy loss and inefficient ventilation.
• Retrofitting energy saving measures to an existing classroom resulted in 31% energy savings
  A new classroom built to enhanced standards above Oregon code resulted in 35% savings in comparison with a new unit built to existing code.
• A comparison of new “off-the-shelf” energy-efficient and standard portables found that building commissioning and proper operation are critical to proper building function. On-site commissioning should include air sealing of the marriage line and other leaks, HVAC system and controls, ventilation air flows, and proper thermostat programming.

Future project work will include developing specifications for the purchase, construction, set up, and operation of portable classrooms; preparing recommendations for low-emitting paints, furniture, and flooring; and building an advanced design portable classroom that incorporates special roof sealing, natural daylighting, and renewable resources.